Every wonder how "The Clapper" works? This
circuit will turn on and off based on a loud sound such as clapping your
hands. You can adjust the sensitivity (how loud of a sound will activate
the circuit) from a pin drop to a Mack Truck Horn. Very practical for a variety of projects.
Add a relay to turn on a light when your
dog barks, or set of a siren when an intruder makes a loud noise.